ABSTRACT
Objective Aiming at improving biomechanical strength of the anastomotic stoma as well as reducing tissue thermal damage, a novel radiofrequency (RF) tissue welding electrode was developed. Methods A novel electrode with a hollow structure on the surface ( the plum electrode) was designed and the ring electrode was used as control group to conduct the welding of intestinal tissues based on RF energy. Biomechanical properties of anastomotic stoma were studied by shear test and burst pressure test. The tissue thermal damage during welding was investigated by finite element electro-thermal-mechanical multi-field coupling simulation analysis and thermocouple probe, and the tissue microstructures were also studied. Results Under 120 W RF energy, 8 s welding duration and 20 kPa compression pressure, the anastomotic stoma had the optimal biomechanical properties. Compared with the ring electrode group, biomechanical strength of the anastomotic stoma in plum electrode group was higher, with the shear strength and burst pressure increasing from (9. 7±1. 47) N, (84. 0±5. 99) mmHg to (11. 1±1. 71) N, (89. 4±6. 60) mmHg, respectively. There was a significant reduction in tissue thermal damage, and intact and fully fused stomas could be formed in anastomotic area. Conclusions The proposed novel electrode could improve biomechanical strength of the anastomosis as well as reduce tissue hermal damage, thus achieve better fusion. The research result provide references for realizing the seamless connection of human lumen tissues
ABSTRACT
Objective The ileum of porcine intestines with radiofrequency (RF) energy was fused through a novel linkage-type pressure controlled electrode, so as to verify feasibility and security of intestinal reconstruction in the RF energy tissue fusion technology. Methods Fresh porcine intestines were fixed on negative electrode in the order of ‘mucosa-serosa’, and then different compressive pressures （497，796，995，1 194，1 492 kPa）and RF energy were applied to the tissues through positive electrode of pressure cone to complete intestinal anastomosis. Biomechanical properties of the fused area were studied by tensile strength and bursting pressure test, and the thermal diffusion and tissue microstructure also studied. ResultsThe anastomotic tensile strength and bursting pressure could reach （8.73±1.11） N and （8.29±0.41） kPa, respectively, when the energy output power, pressure and welding time were 160 W, 995 kPa and 13 s, respectively, and an intact microstructure with little free collagen in the fused area could be observed. Conclusions The technology of RF energy-based tissue fusion could accomplish fast and stable intestinal tract reconstruction, showing great potential in clinical application. It is of great significance to shorten the operation time, simplify the operation process and improve the operation quality.